Reduced NO-cGMP Signaling Contributes to Vascular Inflammation and Insulin Resistance Induced by High-Fat Feeding

作者：Norma O. Rizzo, Ezekiel Maloney, Matilda Pham, Ian Luttrell, Hunter Wessells, Sanshiro Tateya, Guenter Daum, Priya Handa, Michael W. Schwartz, Francis Kim · 发表于：Arteriosclerosis Thrombosis and Vascular Biology · 年份：2010 · DOI：10.1161/atvbaha.109.199893 · 被引用次数：96 · 研究领域：Nitric Oxide and Endothelin Effects、Regulation of Appetite and Obesity、Adipokines, Inflammation, and Metabolic Diseases

OBJECTIVE: Diet-induced obesity (DIO) in mice causes vascular inflammation and insulin resistance that are accompanied by decreased endothelial-derived NO production. We sought to determine whether reduced NO-cGMP signaling contributes to the deleterious effects of DIO on the vasculature and, if so, whether these effects can be blocked by increased vascular NO-cGMP signaling. METHODS AND RESULTS: By using an established endothelial cell culture model of insulin resistance, exposure to palmitate, 100 micromol/L, for 3 hours induced both cellular inflammation (activation of IKK beta-nuclear factor-kappaB) and impaired insulin signaling via the insulin receptor substrate-phosphatidylinositol 3-kinase pathway. Sensitivity to palmitate-induced endothelial inflammation and insulin resistance was increased when NO signaling was reduced using an endothelial NO synthase inhibitor, whereas endothelial responses to palmitate were blocked by pretreatment with either an NO donor or a cGMP analogue. To investigate whether endogenous NO-cGMP signaling protects against vascular responses to nutrient excess in vivo, adult male mice lacking endothelial NO synthase were studied. As predicted, both vascular inflammation (phosphorylated I kappaB alpha and intercellular adhesion molecule levels) and insulin resistance (phosphorylated Akt [pAkt] and phosphorylated eNOS [peNOS] levels) were increased in endothelial NO synthase(-/-) (eNOS(-/-)) mice, reminiscent of the effect of DIO in wild-type cont...